Power transmitter



June 18,1940. c; SAUER POWER TRANSMITTER Filed June 5, 1957 3 Sheets-Sheet 1 INVENTOR; George Samar,

BY W

' ORNEY'S.

WITNESSES:

June 18, 1940. G. 'SAUER POWER TRANSMITTER 3 Sheets-Sheet 2 Filed June 5, 1957 WITNESSES:

INVENTOR:

George Sauer,

BY W

RNEYS.

June 18, 1940. SAUER 2,205,176

POWER TRANSMITTER Filed June 5. 1937 3 Sheets-Sheet s WITNESSES: 1 INVENTOR George Sauer,

Patented June 18, 1940 UNITED STATES POWER 'TRANSMITTER George Sauer, Berwyn, Ill. assignor to Union Special Machine Company, Chicago, Ill., acorporation of Illinois Application June 5, 1937, Serial No. 146,551

6 Claims.

My invention relates to driving units and power transmitters, and is adaptable and advantageous for motor driven machines such as sewing machines, and especially where the motor drives through a belt. I aim to provide for maintaining' the belt properly taut, and for its easy and convenient adjustment to tighten or loosen the driving connection, utilizing the motor itself for the purpose. In using a clutch between the motor the parts or machinery driven by it, I may dispense with the use of any spring in the clutch itself, for the purpose of throwing it out, accomplishing this through the braking means employed to stop the driven parts. Various other 15. features and advantages of the invention will ap-v pear from the following description of a species or form of embodiment, and from the drawings.

1 In the drawings,

Fig. I is an end View of the power transmitter applied to a sewing machine, certain parts being partly broken away or in section.

Fig.- II is a side viewof the transmitter, with certain parts in vertical'longitudinal mid-section, the section being taken somewhat irregularly in order to show various parts more clearly.

Fig. III is a plan view of the transmitter.

Fig. IV is a tilted or perspective view of a bolt.

In Fig. I, the transmitter is shown mounted beneath a sewing machine table it and drives the sewing machine H through a belt l2 (here shown as oi-V-section) that extends around suitably grooved pulleys i 3 and i l, the pulley [3 being associated with or forming part of the transmitter, and the pulley M being mounted on the main drive shaft R5 of the sewing machine. As shown in Figs. I, II and III, the transmitter comprisesan (electric) motor it which is attached, as by bolts H, to a support or base plate mounted for movement down or up relative to the 4G fixed support or table iii, to tighten or loosen the belt it. For this purpose, the supporting plate or motor mounting 20 may be pivoted or iulerumedon a pivot pin or bolt 2! extending, substantially parallel with the motor shaft 22, through downturned marginal flanges 23 at opposite endsof the supporting plate, and through rearward-projecting ears of a support bracket 2-5, which may be secured to the underside of the table W at or adjacent its rear edge by bolts 25. 50 As shown in Fig. I, the relation of the pixot axis 2 i of the support 28 to the belt i2 and the motor it is such that the weight of the motor acts to tighten the belt. Besides the rotary driving member orpulley l3 and the motor i6, the power unit of the transmitter includes an interposed (Cl. Pl-242.13)

(friction) clutch 2l,-all these parts being preferably coaxial with the motor shaft'22. The clutch 21 serves as a means of controlling the operation of the pulley i3 and the parts driven therefrom, and may be aided in this by a braking mechanism for stopping the driven parts when the clutch is thrown out, as described hereinafter.

Belt-tightening downward movement of the motor It may be limited by any suitable means, such as a bolt 30 Whose T-head at is engaged in a transverse slot 32 in a longitudinal cylindrical upward embossment 33 of the base plate 20, and whose screw-threaded shank extends up through a hole in the table l0 and has adjusting means, shown as consisting of nut(s) (i l, 35, which are conveniently accessible above the table for manipulation by an operator seated in front of the table. As shown in Fig. I, the'nut 34 is a knurled adjusting nut, while the nut 35 is a wing lock nut. Between the nuts 34, SEE-and the table H] may be interposed a vibration-absorbing metal capped rubber Washer 36, shown as seated in a recessed seat 31 in the top of the table. As best shown in Figs. II and IV, the head 3| of the bolt 30 includes a squared portion 38 which engages in the slot 32 in the base plate 20, to prevent the bolt from turning. To urge the power unit, including motor i6 and support Zil, downward and keep the belt l2 taut,even regardless of the motor weight,--a helical compression spring 40 may be mounted around the bolt 30, to act between a washer ll in a recess 42 in the lower surface of the table it and a washer 43 engaging the top wall of the rounded portion 33 of the supporting plate 29. As shown in Figs. I, II and III, this portion 33 is provided with an extra bolt slot 32, for use in cases where a different location of the bolt 30 is desirable.

With the sewing machine shaft i5 and the motor 16 rotating counter-clockwise,as usual, and as shown by the arrow in Fig. I,the torquereaction of the motor about pivot 2i opposes the downward belt-tightening tendency of the motor weight and of the spring it]; but the spring-is made strong enough to overcome this and assure an adequate dominant belt-tightening force under all conditions. This allows of locating the motor I6 and its pivot 2| (as shown) well to the rear of the table board in on which the sewing machine II is mounted, so as to give room for that portion of the machine bed (not shown) which usually extends through the table board, as well as for the knees of the sewing machine operator seated in front of the table.

As shown in Fig. II, the clutch 2'! includes a driving fly-wheel member M whose cylindrical hub is mounted on the motor shaft 22 and is compelled to turn therewith by a key and keyway engagement indicated at 46. A ball bearing 41 may be interposed between the fly-wheel M and the motor casing 48, to take the end thrust of the clutch 21, so that it shall not be transmitted to the motor shaft 22 and the rotating parts of the motor itself (not shown). The fly-wheel 44 may be fixed to the shaft 22 by a set-screw 49 in its hub 45. With the driving clutch member M coacts a driven clutch member 50 whose cylindrical hub 51 is rotatably mounted on the flywheel hub 45. lhe hub 5i may be provided with a separate bushing or liner 52 of suitable bearing material. The pulley I3 is mounted around the hub 5| and secured to the member 50 by screws 53. The driven clutch member 50 may have a conica1-surfaced friction liner 55 for engaging a corresponding conical surface on the driving clutch member 54, and may have a conically beveled (outer) braking surface 56, for coaction with other parts of a braking mechanism for controlling and stopping rotation of the parts driven through the clutch,--as described hereinafter. As shown in Fig. II, the hub 5i includes an endcap 5'1 which is pressed on the end of the bearing bushing 52 and has a reduced end portion 58, around which is mounted an anti-friction ball bearing 59.

For operating the clutch 21 and the brake mechanism just referred to, a rocking lever 50 is fulcrumed on the support 29, about an axis formed by a pivot pin or bolt 5i extending sub stantially at right angles to the pivot bolt 2!,

and mounted in apertures in ears 63 at opposite sides of the base plate 20. As shown, the actuator lever 6b is fulcrumed between the spaced apart ears or bracket arms 63 of the motor support 20. These ears 63 may be formed by downward extension of the marginal flanges 23 of the plate 20. One arm of the lever is apertured for a flexible and universal pivotal engagement or connection with the eye of an operating link rod 64, while its other arm carries a brake block 66 whose acting face is beveled in correspondence with the conical bevel of the periphery 56 of the driven clutch member 50, with which it coacts.

, The brake block 55 is seated in a vertical channel in the enlarged end of the lever 60, and secured by a bolt 67. The lever 69 also has a downward projecting arm 68 which carries round headed abutment bolts 69 for engaging the ball bearing 59 at either side of the axis of the motor shaft 22,or of the reduced cap portion 58 on which the ball bearing is mounted. As shown in Figs. 1, II, and III, a helical torsion spring ll) is mounted around the bearing hub of the lever 60, with one end engaging the supporting plate 25 and the "other engaging the lever: this spring Til acts to urge the brake block 66 against the periphery 56 of the driven clutch member 58, and preferably has suflicient braking force to stop the driven parts quickly. As .iown in Fig. II, a lubricator 'H is mounted on the arm 58 of lever 50 between the round headed bearing bolts 69, with its delivery tube 72 extending into the interior of the cap portion 58 to deliver oil for lubricating the bearing surfaces of parts on the motor shaft 22.

When it is desired to drive the sewing machine H, the operator operates a foot treadle (not shown), or other means connected to the rod 64, so as to lift the brake shoe 6% from the driven clutch member 5a and at the same time push the latter to the left into engagement with the driving clutch member 44. When it is desired to stop the machine, the operator has only to release the treadle or other actuator for the rod 64, when the spring 10 will automatically throw in the brake 66 against the conically beveled periphery of the driven clutch member 59, thereby pushing the member 5!! to the right to throw out the clutch 27, and also stop the driven parts. When it is desired to adjust the support 20 and the motor I6 relative to the machine-supporting structure If] to tighten or loosen the belt l2,to take care of a difference or change of length, or to facilitate the removal or installation of a belt,-the operator has only to loosen the wing nut 35 and then lower or raise the support 20 by a knurled adjusting nut 34, afterward retightening the wing nut 35 to relock the nut 34. The universally flexible eye-connection of the '1ink-rod 64 to the lever 60 allows the link-rod to operate eifectively in all angular positions of the support 20 about its pivot 2|, within the normal range of angular relations between the parts 20 and If] that is permitted by the bolt 30, or by the belt I2.

Having thus described my invention, I claim:

1. A driving unit for sewing machines and the like comprising a motor and a rotary driving member, with interposed clutch means; means for motuiting said motor on the supporting structure of the machine to be driven, for movement relative thereto to tighten or loosen the driving connection between said driving member and said machine; means for adjusting said mounting means and said motor relative to said supporting structure; an actuator for said clutch means mounted on the aforesaid mounting means, and thus moving with said mounting means and said motor relative to said supporting structure; and an operating connection for said actuator flexibly pivoted thereto to operate the same in all normal angular relations of said motor to said structure.

2. A driving unit for sewing machines and the like comprising a motor and a driving member, with interposed clutch means; means for mounting said motor on the supporting structure of the machine to be driven, for movement relative to tighten or loosen the driving connection between said driving member and said machine, comprising a motor support with spaced apart arms; means for adjusting said support and motor relative to said supporting structure; an actuating lever for said clutch fulcrumed between said bracket arms about an axis substantially perpendicular to the motor shaft and thus moving with said mounting means and said motor relative to said supporting structure; and an operating connection for said lever universally pivoted thereto to operate the same in all normal angular relations of said motor to said structure.

3. The combination with a pulley and shaft to be driven, and a fixed support therefor; of a motor with mounting pivoted to said support eccentrically to its shaft, and a pulley to be driven by said motor shaft, with means for controlling its operation; a driving belt connecting the latter pulley to that on the aforesaid shaft to be driven, arranged to be tightened by swinging of the motor about its pivot on said fixed support; an operating lever for said controlling means pivoted to the motor mounting; and an operating connection for said lever universally pivoted thereto, so as to be operable in all normal angular relations of said motor to said fixed support.

4. The combination with a pulley and shaft to be driven, and a table support therefor provided with a pivot-fulcrum bracket; of a base plate with laterally projecting flanges at its opposite sides and ends; a fulcrum pivot extending substantially parallel with said pulley shaft through said pivot-fulcrum bracket and through the end flanges of said base plate; a motor on said base plate having its shaft parallel to said fulcrum pivot and said pulley shaft, with a pulley on the motor shaft and a friction clutch and brake for controlling its operation by the motor; a driving belt connecting the latter pulley to that on the aforesaid shaft to be driven, and arranged to be tightened by the motor weight; a spring acting between said support and said base plate, in aid of the belt-tightening action of the motor weight; an operating lever for said friction clutch and brake, and a fulcrum pivot therefor mounted in the side flanges of said base plate, substantially at right angles to the aforesaid shafts and fulcrum pivot; means for limiting the downward, belt-tightening movement of the motor connected to said base plate, and extending and adjustable above said table support; and an operating connection for said lever universally pivoted theretoso as to be operable in all angular relations of said base plate to said table support, within the range permitted by the aforesaid adjustable limiting means.

5. The combination with a shaft to be driven having a. pulley, of a power unit comprising a motor and a pulley with interposed clutch means for interconnecting and disconnecting them, brake mechanism controlling rotation of the parts driven through said clutch means, a belt interconnecting said pulleys, a pivotally mounted support for said power unit with its pivotal axis substantially parallel to the motor axis, and so related thereto that movement of said power unit about its said pivotal axis tightens the belt, an actuating lever for said clutch means and brake mechanism fulcrumed' on said support, and an operating connection for said lever flexibly connected thereto so as to be effective notwithstanding angular movement of the support about its pivot.

6. In a motor transmitter, the combination of a power unit comprising a motor and a pulley with interposed clutch means for interconnecting and disconnecting them, a belt for connecting said pulley to parts to be driven by the motor, a support for said power unit comprising a plate with laterally bent apertured portions, a supporting pivot for said plate extending through opposite apertures of such portions substantially parallel with the motor axis, a pivot extending through opposite apertures of other such portions substantially at right angles to the first mentioned pivot, and means rockable on said last-mentioned pivot to control said clutch and the rotation of the parts driven through it.

GEORGE SAUER. 

